I am about to order Dish for one HD and SD tv. It is my understanding I will receive one box (622 & recorder) which will also provide separate tuning for the SD tv in another room. My house is wired for cable in the typical configuration: coax from several rooms leads to a box in the garage where it is attached to the TV input. Question: is another coax required between my HD and SD tvs? Boy, I'll bet that is a dumb question.